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startreker1

Would a computerized scope be better

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Posted (edited)

I have an 8" apertura Dobsonian and altho I finally did get the collimation understood and done, I still am having problems with actually locating objects in the sky. My last question I asked on here was about the finderscope alignment, and I understand better what I need to do now, thanks to a reply I received, and watching a video. If I were to sell this one, and get for example a celestron se 6 or 8 (may be out of my budget tho) Schmidt-Cassegrain computerized, would that really keep me from being so frustrated doing these searches, because the computer will do it for me, once I locate 2-3 major objects in the sky and put them into the computer? If the telescope is put away, and I take it back out again, will that computer know where to find the same objects for me again on its own, if I do have the telescope level? I am a beginner, and honestly, I feel this dobsonian has been a pain with all the collimation necesssary, and the weight especially, being I always have to take it apart in 2 pieces and carry them around. I thought of a cart or wheels on a base, but still I have the issue of the bulk and weight. I'd like some opinions please. Almost thinking if maybe I should give up this hobby, due to the frustrations. Would I also have to be doing collimations on that celestron type too? Thankyou for your advice and thoughts.

Edited by startreker1
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Posted (edited)

I would say that if you're having an issue with its bulk and weight alone then this would be the first reason to switch to a smaller and lighter scope. If you find yours a pain to move around then you will be less likely to use it period which defeats the whole purpose of this hobby, so yes, if i were you i would switch to something you're going to enjoy using a lot more often. Having said that, every scope requires collimation, it is a bit easier to collimate SCT scopes because you're only dealing with the secondary and 3 screws generally.

From a finding objects and computerized scope POV, they do require alignment every time you take them out, once you learn how to align it its like riding a bike, you'll know how to do it because the steps are the same every time and yes, you will see many more objects in one night once your scope is aligned and ready. It really helps to know how to find objects though, you would really benefit from a book like "Turn Left at Orion" or "Nightwatch" by Terence Dickinson. There are programs like Stellarium which are free and you can install on your computer, they're fun to use and really help alot.

Edited by Sunshine

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Posted (edited)

 

The question of whether to find objects by manually aiming the scope or using go-to technology has long been debated.

Probably one is not harder or easier than the other, once you get the hang of it that is....

For many like myself manually star hopping is a pleasure, and watching others fiddling around for ages with setting up and using a hand set looks like a pain in the derrière.   And watching someone trying to acquire sky objects manually and not succeeding is painful too.....

I think it’s best to find out what suits you by reading up online or in books and magazines then try it in practice.  As you already have an 8” Dob, assuming it’s a manual version, then your cheapest option is to learn how to use it.  Do an online search for how to manually find sky objects, the book already mentioned - Turn Left at Orion - is brilliant and well worth getting.  Gradually you should find that acquiring the brighter objects is a snap, and then you can move on to the fainter stuff. After a year or two you will hopefully find yourself not wanting to do it the hard way using technology that just slows you down and frustrates.  You may find precisely the opposite of course.......only you can finally decide what suits you, not me.

The question of collimation often comes up. It’s really not hard, again once you’ve learned how.  For many, it’s a non issue. Some find that collimation is necessary every time you set up. But if that’s the case then with a solid tube Dob perhaps something is loose, too much gap between the primary mirror and clips - just a smidge is enough. Or maybe the spider vanes are not secure. If something can flop about then collimation is easily lost.....

Please do not give up the “biggest” hobby there is, good luck.....

Cheers from Ed.

Edited by NGC 1502
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A Goto telescope would certainly make it easier to find objects in the sky, once you master the setup, which has to be repeated each time you take the outfit outside and set it up for use.  I should point out that some people just don't get on with GoTo scopes (though I wouldn't want to use a big scope without it.)  There are ways of simplifying the setup procedure, such as using the Starsense accessory, or a GPS module (or both).  If you know the sky well enough to identify various of the brightest stars, you can use a 2-star alignment which is quicker than the 3-star and gives the same result. Doing a 2-star alignment with a GPS-equipped mount is fairly quick and painless.

Yes, you could get a C6 SE or a C8 SE, and both are excellent outfits for visual observing, and also light and compact.  I should point out though that you can buy GoTo Dobsonians, or Dobsonians with digital setting circles, which might be cheaper.

As for collimation, I have three catatroptic scopes - two SCTs and a Maksutov. I had to collimate one of the SCTs when I bought it second hand about two years ago, and have not needed to touch the adjustment since, and the other two not at all.

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Posted (edited)

I'm pretty new to telescopes myself but somehow seem to have collected a few in a short space of time! To me the dob just doesn't seem user friendly (yeah others will disagree) but bumping the tube to shift your view seems too crude and inaccurate compared to slow-mo screws on the EQ mounts. For a beginner I can imagine it being very frustrating trying to make tiny adjustments until you get a feel for just how to... To me a decent EQ or AltAZ seems a much nicer engineering solution, tho for sure you get more aperture/£ going the dob route. Catch-22 tho as if it ain't working for you, interest rapidly wanes and you give up altogether, just my 2 cents 🙂

The only dob-ish scope I have is the tiny NatGeo 76/350 so not a fair comparison, I know. To make very small movements is fraught with overshoots and irritation I find. Had originally got that as maybe something the grandaughter could use for looking at the moon etc, being so compact but am not so sure having played with it. Now think the Tal-M would be a better bet for her when I make it able to use just one pier tube to get the OTA down to her height ;) 

I've a Skywatcher 130 Newt on EQ2 mount, reasonably light to move but being a long tube still awkward to carry out to the garden in one go, usually take the OTA off and do that in 2 moves. Once roughly N aligned its easy to follow objects with the slow-mo controls and reasonably smooth, does have the RA motor unit too when I want to use it. Being lazy I rough align to N with a compass which seems to work ok for visual. 

The Tal-M and Tal-1 newts are heavier but easier to lift and shift being pier rather than tripod mounted and again the slow-mo controls make fine shifts easy. For the Tal100RS refractor on EQ5 I've upgraded that with a SynScan goto dual motor GoTo. Wanted to be able to motorise RA to give relaxed viewing and maybe try some imaging later on, but landed on an EQ5 with synscan upgrade and tripod for a nice price so bought it. Had to transfer the motor drives to the EQ5 that came with the Tal as the one it was fitted to sticks in a couple places, but now it runs slick and smooth. Sadly not had a chance to use it under the stars yet, what with weather, poor skies, work and family stuff but I have tested it and done some learning in daylight, so think I should be ok. Being techy I guess too that I'd gravitate to this type of toy ;)  Alignment shouldn't take much more than a few mins from what testing I've done so far.

As with most things new, patience is key as things can take a while to learn with frustration and setbacks along the way. I spent a year overhauling binoculars so when I started getting telescopes I was already comfortable with dismantling optics and collimating (much easier that aligning 2 sets of optics). All my gear has been sourced S/H via the bay and while some could do with some restoration (paint and mechanicals, not optics/mirrors) I feel I've bought reasonably well and end result is a selection of very useful gear that I'll enjoy using and restoring. 

In the end the real choice is yours, either try to overcome the frustration and learn how to use the dob, perhaps practise in daylight on distant targets and learn the touch needed to nudge it, or if poss try to meet up with someone who has a GoTo and can show and maybe let you try it so you know if it works for you, before spending a wedge only to find that it isn't. Are you OK finding your way around the skies with binoculars? That may be a low-cost way to learn how to navigate if you've not already tried it. I'd say if you do opt for a GoTo, do the same as I have, play with it in daylight when you can see what you're doing, learn how to do the 1/2/3-star alignment routine and select targets, park the scope in the home position etc. That'll save lots of frustration when you actually want to be using it in the dark and maybe reduce your setup time aligning it to just a few mins.

HTH

Edited by DaveL59
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Good previous post from DaveL59.   I’d just like to add that although I really like manual Dobs, and a Dob with smooth movements is a pleasure, a Dob with sticky movements is a right royal pain.

Top tip - whatever works for you and gets you under the stars is the way to go 👍

Ed.

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Morning! From a fellow beginner (well a couple of years but all of this is still pretty new to me) my first telescope was a manual dobsonian, I learned my way around the sky with it and the help of a startracker app on my phone. I really enjoyed that dobsonian! I got rid of it and bought a telescope with Goto and if I am honest, I struggled with the Goto, it's one thing more to worry about, with the power pack etc. To this day I really miss my manual dobsonian, so much I am thinking of replacing my 250 Dob which has Goto for a 200p manual Dob..

I've just bought a 127 mak that has a WiFi AZ mount, and I have found it much easier than the Goto, I would recommend the WiFi version and the SynScan app to anyone as it is just so easy to use and very portable, the viewing of planets through it have been very good.  I guess it also depends on what you want to observe.

Don't give up, your frustrations will fade when you first see the planets, shadows on the moon etc. Do you live anywhere where perhaps you could meet up with someone else who has a dobsonian who could help you?

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The Synscan system gives you GoTo, but it also gives you accurate tracking. You can use the manual buttons to select an area of sky, and then change eyepieces to get the desired view, in the knowledge that the view will not have drifted away during the change.

Geoff

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Don't give up!

My experience of new scopes is that they sometimes have something not quite fastened correctly, or not quite aligned.
Secondhand scopes may be better or worse.
Then new scopes sometimes have poor accessories to meet a price point.

With an 8" newtonian on dobson mount, you have a scope that is easy to sort out and easy to modify to suit your use.

If the dob mount is a bit sticky, take it apart to find out why. A bit of silicon grease on bearings may be all it needs. Or a fraction of a turn backing off a retaining bolt.
There may be a bit of muck or dust ona bearing surface.

The scope. Yes look at the mirror fixings as suggested earlier. My experience of 8" and 10" newts is that they hold collimation quite well for everyday viewing.
Unless of course you give them a really good knock on door frames on the way from the house to the garden.
I used to regulalry travel with an 8" newt on the car back seat and don't remember any collimation issues..

On the rare nights that you can push the magnification to the scope limits, then accurate collimation becomes more important.

On the finderscope - which is a vital part of the scope - what are you using?
There is no 'one size fits all' solution.

I hate the straight through optical finders often supplied with this scope type and have always swapped for a right angle finder, positioned near the scope eyepiece.
For me, a 9x50 right angle finder is first fitting to a newtonian in this size range.

Some love a Telrad finder. I never liked them.
I use a Rigel Quickfinder for basic alignment. Some hate them.

As for straight through red dot finders. They can be good. Some should be put with your papier mache teapot collection.
I have seen examples with a spot so bright that it obscures Venus, Jupiter, etc.
Others have had a tinted viewscreen that dims anything less bright than Venus to invisibility.

Keep going and don't sell the scope just yet. Keep asking the questions.

David.
 

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On 17/08/2019 at 16:48, startreker1 said:

I have an 8" apertura Dobsonian and altho I finally did get the collimation understood and done, I still am having problems with actually locating objects in the sky. My last question I asked on here was about the finderscope alignment, and I understand better what I need to do now, thanks to a reply I received, and watching a video. If I were to sell this one, and get for example a celestron se 6 or 8 (may be out of my budget tho) Schmidt-Cassegrain computerized, would that really keep me from being so frustrated doing these searches, because the computer will do it for me, once I locate 2-3 major objects in the sky and put them into the computer? If the telescope is put away, and I take it back out again, will that computer know where to find the same objects for me again on its own, if I do have the telescope level? I am a beginner, and honestly, I feel this dobsonian has been a pain with all the collimation necesssary, and the weight especially, being I always have to take it apart in 2 pieces and carry them around. I thought of a cart or wheels on a base, but still I have the issue of the bulk and weight. I'd like some opinions please. Almost thinking if maybe I should give up this hobby, due to the frustrations. Would I also have to be doing collimations on that celestron type too? Thankyou for your advice and thoughts.

 

On 17/08/2019 at 16:48, startreker1 said:

I have an 8" apertura Dobsonian and altho I finally did get the collimation understood and done, I still am having problems with actually locating objects in the sky. My last question I asked on here was about the finderscope alignment, and I understand better what I need to do now, thanks to a reply I received, and watching a video. If I were to sell this one, and get for example a celestron se 6 or 8 (may be out of my budget tho) Schmidt-Cassegrain computerized, would that really keep me from being so frustrated doing these searches, because the computer will do it for me, once I locate 2-3 major objects in the sky and put them into the computer? If the telescope is put away, and I take it back out again, will that computer know where to find the same objects for me again on its own, if I do have the telescope level? I am a beginner, and honestly, I feel this dobsonian has been a pain with all the collimation necesssary, and the weight especially, being I always have to take it apart in 2 pieces and carry them around. I thought of a cart or wheels on a base, but still I have the issue of the bulk and weight. I'd like some opinions please. Almost thinking if maybe I should give up this hobby, due to the frustrations. Would I also have to be doing collimations on that celestron type too? Thankyou for your advice and thoughts.

Hi. I'm so sad to read you saying you're thinking of quitting hobby due to problems with finding objects and hauling your 'scope around! I'm a newbie myself, 10 months in, and on my 3rd 'scope, an 8inch Dob like yours. I struggled terribly in my first few months with finding objects, and simply trying to make sense of the sky and my equipment! I tell you though, if you persevere, i promise you when you get the hang of things you will never look back! You just need to be patient. I found watching video bloggers on YouTube who do astronomy, astrophotography etc etc etc were/still are a fab source of knowledge and help. I'd also suggest you buy a book called "Turn left at Orion". It's a brilliant book for beginners like us. Please try and persevere because it will DEFINITELY be worth the effort when you see some of the awesome objects up there! Star hopping/searching for objects will become second nature to you in the coming months! Best of luck!

Wes, Liverpool, UK.

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There is no right or wrong way only a route that has has the right setup, the right scope and gets you observing with minimum fuss so you enjoy it and can maximise your time. When you are new to this hobby it can take a fair bit of experimentation to get there, and it often means losing a few quid on the way, we have all been there.

Star hopping can be very frustrating when you are new or even when experienced because I found it left a very vague area where I did not know if I was genuinely missing a target or whether it was light pollution or seeing conditions that were stopping the target from being seen. I personally do not need the thrill of the chase in finding objects manually star hopping, if I don't see them it will not be because I was not in the right place. In any case with UK skies being so challenging and observing time at a premium in between cloud breaks the reason to be pragmatic in your approach and make this hobby easier is prevalent.

I mostly operate in a halfway house of sorts with push to systems, that is using digital setting circles, where after a simple alignment wherever I push the scope to a small computer tells me what is in the area and which direction to push the scope to get there. Of course there is a choice to make a list before I head out as well. What it does is remove the doubt when I am out there. A fully computerised goto and tracking system will do the same as long as it is set up correctly. Telescope maintenance is in addition to all this whether manual or not. 

When you drive somewhere for the first time you may use a map or a satnav, after a few times going there you remember where it is so it becomes easier. After a period of time without visiting you might forget and need the map again. Astronomy is like this. There is no shame in being poor at star hopping, it depends on many factors, time, experience, eye condition etc.

Therefore I would suggest you get a go to system in addition your manual dob if finances permit. The goto will get you seeing objects quicker and boost your confidence and enjoyment. Later on you might find the manual dob a lot easier to use, if not stay with goto and let the dob go. One other thing joining a local club can really help, you get to see and use other telescopes and this will help you make your choices.

Edited by JG777
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Best thing to do get a telrad or rigel 

Also the dob is really low 4ft about and that's looking upwards. So i could see y bending down like that and trying to fi d object may not work. Thatd y I would recommend getting that scope on the eq5 version. Even the tripod st its lowest point puts the ep perfect for looking and finding objects.

A 8 inch used sct can be sought and they also sell it on a eq5 mount too.

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Personally I wouldn't be without my Goto Dobsonian purely because once set up it knows where loads of interesting things are and will take itself to the right point in the sky to see them.  Goto's on other scope types do the same. 

However, whatever scope you get you do have to still start off by teaching it/calibrating it and you need to do this each time you use it - this is not without problems for some folks (myself included!).  For this you need to be able to find by eye some named bright stars and then be able to tell if the telescope is looking at the correct star so you can adjust to the centre of the eyepiece and then confirm to the software that you have done so.  You also need to be able to start off with it pointing North and for this it is handy to be able to first align on the pole star and drop the scope down to the horizontal position.   Thus you need a means of locating a least a star or so in the sky by name and then pointing the scope at it.  Identifying a suitable star like the Pole star isn't actually that difficult (there are lots of computerised bits and bobs to help, like Stellarium for the mobile phone), but, as you have found pointing a telescope at a star in the vastness of a black sky isn't as easy as you might have hoped.  

Thus, you do need to get the finderscope alignment sorted out and not forget that this will need checking and tweaking every time you take it off and put it on again.   Basically as you have discovered unless the telescope and the finderscope point at the same spot you can't then look through a finderscope find a start and have the telescope looking the same thing.  The easiest thing to do is on the day you want to use the scope start setting it up in the afternoon (do NOT point it anywhere close the sun though).  Find a recognisable object some distance away on the horizon and get in the centre of the scope fitted with your highest mm eyepiece.  Then use the positioning adjustment knobs on the finderscope or its holder to get the same object in the centre of the finderscope.  Now when you find a new object in the finderscope because it is looking in the same place as the telescope the object should be viewable in the eyepiece of the telescope. 

Now there is also a good chance that you might be starting with a straight through optical finderscope - I wrestled with one of these for all of about 4 hours before a purchased a right-angle correct image one.  However, even that didn't solve the issue for me.  What worked for me was a cheap celestron style red dot finder - I didn't find any need for these fancy Telrad versions, Mine was a tenner second-hand from ebay, and I got a cheap 3D printed holder from ebay and mounted the two together

Finders2.jpg

 

I find that providing the optical finder is aligned accurately with the telescope that the RDF can be just 'thereabouts', esp.  I have taken a look in the afternoon and know just how far out it might be (you could also take time to tie in both accurately, but I find it isn't worth the hassle,).  I find with this combination I can find anything I can see in the sky in the telescope in about 15 seconds flat, yet before I got the RDF I'd spend 40+ minutes sometimes with the optical finder and still not get there.  As it is I find the target with the RDF (I task I find silly easy) by then, even if not perfectly adjusted with the optical finder) the star of interest is within the view of the optical finder (which I have aligned with the telescope.  I then centre the star in the optical finder and 'bingo' its in the centre of the telescope.  I hope this helps.   FWIW if I had the choice of just an optical finder or just a red dot finder (RDF), I'd take the RDF like a shot.

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My opinion is find a club and see what is around, then decide. Which bit of the UK or world are you.

All scopes have poor aspects, you basically have to give up something. You have aperture and usually a reasonably wide view, but do not have the goto ability nor the tracking.

One of the SE strains of scope will give you the goto and the tracking but you will lose the wide views and some aperture, setting up can then be not so straight forward.

My scope for here is a small Az GTi and a Skywatcher 72ED, not going to go big was a decision I made. Much less aperture but I find it an easy to use scope. I read that the mount will take an 80ED, but no more.

You need to determine the positives and the negatives of any scope and system. If my little small aperture 72ED gets things in view I would consider it better then anything significantly bigger that fails.

Also just purchased a Herschel Wedge for solar viewing. Small scope maybe, but usable and flexible.

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